It is known that ultraviolet light of sufficiently short wavelength can be used to kill microorganisms. The ultraviolet light has a mutagenic effect on a microorganism's DNA, preventing reproduction and killing the microorganism. Ultraviolet light having a wavelength of 240-280 nm, also known as UV-C, appears to have the greatest germicidal properties.
Ball, U.S. Pat. No. 4,998,504 discloses a disposable pet litter box having a transparent container disposed within a sanitizing support container. Cat litter is placed in the transparent container. The support container has ultraviolet light producing lamps around its interior. The lamps, however, are exterior to the transparent container containing the litter. The UV light is transmitted though the transparent container and penetrates into the cat litter, to kill microorganisms.
Gantt, U.S. Pat. No. 6,857,391 discloses an animal toilet enclosure. The enclosure has floorboards arranged similar to louvers, which pivot to an open position, after the toilet has been used, to deposit the contents into a disposal hopper. Overhead ultraviolet and heat lamps may be provided in the enclosure to semi-sterilize and dry the floorboards.
The prior art devices suffer from various drawbacks, including lack of simplicity, high cost, and attenuation of the intensity of the ultraviolet light caused by transmission through plastic walls or the relative distance between the light source and material to be treated. Thus, there remains a need for an uncomplicated, inexpensive and effective method of treating litter boxes, to reduce potentially harmful microorganisms.